#include <bits/stdc++.h>
using namespace std;

#define int int64_t
#define endl "\n"

using PII = pair<int, int>;
using TII = tuple<int, int, int>;
template<class T>
using V = vector<T>;
using i64 = long long;
using i128 = __int128;
using u64 = unsigned long long;

#define FOR(i, a, b) for (int i = (int)(a); i <= (int)(b); i++)
#define FOR2(i, a, b, c) for (int i = (int)(a); i <= (int)(b); i += c)
#define FORD(i, b, a) for (int i = (int)(a); i >= (int)(b); i--)
#define FORD2(i, b, a, c) for (int i = (int)(a); i >= (int)(b); i -= c)
#define ALL(a) a.begin(), a.end()
#define RALL(a) a.rbegin(), a.rend()
#define lowbit(x) ((x)&(-x))
#define RE return;
#define Yes cout << "Yes" << endl;
#define YES cout << "YES" << endl;
#define No cout << "No" << endl;
#define NO cout << "NO" << endl;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
#define sz size()

void solve () {
    int x, y, k;
    cin >> x >> y >> k;

    int t = __gcd (x, y);

    x /= t, y /= t;

    V<int>f (max (x, y) + 1, 1e18);

    function<int (int)>dfs = [&] (int x) {
        if (f[x] != 1e18)return f[x];
        if (x == 1)return f[x] = 0;
        if (x <= k)return f[x] = 1;

        for (int i = 2;i <= x / i && min (i, x / i) <= k;i++) {
            if (x % i == 0) {
                if (i <= k)f[x] = min (f[x], dfs (x / i) + 1);
                if (x / i <= k)f[x] = min (f[x], dfs (i) + 1);
            }
        }
        return f[x];
        };

    dfs (x);
    dfs (y);

    if (f[x] == 1e18 || f[y] == 1e18) {
        cout << -1 << endl;
    } else {
        cout << f[x] + f[y] << endl;
    }

}

signed main () {
    int Task = 1;

    ios::sync_with_stdio (false);
    cin.tie (nullptr);
    cin >> Task;

    while (Task--) {
        solve ();
    }

    return 0;
}